The fundamental question of how cells of bones and teeth assemble and mineralize their respective matrices in such a coordinated and superbly biofunctional way is still largely unanswered. The Protein Chemistry Unit has been performing a variety of experiments and collaborations to help determine the structure-function relationship of several of the more interesting noncollagenous proteins. Publications fall into four general categories. 1) Two closely related proteoglycans, decorin and biglycan, continued to be central to our interests. Advances have included work on the localization of the endocytosis receptors for BGN and DCN in renal cortex. 2) Advances in the understanding of McCune-Albright Syndrome (MAS) including data indicating that the disease directly affects the osteogenic lineage. Furthermore we have developed a new assay that aids in the rapid detection of the mutation. Using this new procedure, we have detected an unusual mutation causing the disease in a patient with MAS. 3) Bone sialoprotein (BSP) has been shown to have interesting biological properties including the support of cell adhesion, proliferation and migration through the use of specific integrins. 4) Finally we have continued our exploration of the possible role of bone sialoprotein in osteotropic cancers. With our colleagues, we have extended our observations to include expression of BSP in prostate cancer. - Mineralized matrix biochemistry, Integrin-binding sialoproteins, Leucine- rich proteoglycans, McCune-Albright Syndrome